MANILA - Supreme Court Associate Justice Teresita De Castro on Wednesday denied she is testifying against Chief Justice Maria Lourdes Sereno because she held grudge over the latter's appointment as top magistrate in 2012.

De Castro, a former Sandiganbayan magistrate and long-time state counsel, was appointed to the court in December 2007, ahead of Sereno, who first became High Court Associate Justice in August 2010 and ascended to Chief Justice two years later.

"Itong pag-appoint kay CJ Sereno, ano po magagawa ko? the president (former President Benigno Aquino III) appointed her. She was nominated by the JBC (Judicial and Bar Council). What should I do?" De Castro said.

De Castro and Sereno were both nominated by the JBC to replace ousted Chief Justice Renato Corona in 2012. Sereno, among the youngest justices at that time, was appointed by Aquino to head the high court, bypassing other senior magistrates.

De Castro appeared before the House Justice Committee to testify about Sereno's supposed wrongdoings.

During the hearing, De Castro said Sereno violated High Court procedure when she ratified an administrative order without the consent of the Supreme Court en banc.

"I cannot stand idly by when the collegial body of the Supreme Court mandated by the constitution is being undermined. What kind of justice am I if I just accept what is happening that is not in accordance with the law?" she said.

Rocamora tried to press De Castro if she was upset over Sereno's appointment in 2012, but other members of the House Justice Committee came to the magistrate's defense.

"I enjoin everybody to ask relevant questions, and give her (De Castro) the respect according to the office," House Majority Leader Rodolfo Fariñas said.

"Ang hinahanap natin is the fitness (of Sereno). Si Justice De Castro is not at issue here dahil siya ay resource person. The real issue in this impeachment proceeding is the fitness of the chief justice to continue holding public office," House Justice Committee chair Reynaldo Umali said.

De Castro said she had documentary evidence to prove her claims against Sereno, clarifying that she is not acting based on her emotions.